An anti-fuse element utilizing a MOSFET structure is sometimes provided in a semiconductor device. In such an anti-fuse element, a gate electrode and a semiconductor substrate are insulated from each other by a gate insulating film in an initial state, however, when breakdown occurs in the gate insulating film by applying a predetermined voltage thereacross, the gate electrode and the semiconductor substrate are electrically connected to each other. According to this, for example, a redundant circuit becomes available.